This training grant is focused on human development, particularly as it relates to cognitive, social, perceptual, and motor development of infants and young children. Developmental outcome in all these areas is often multi-causal, the aggregate product of many nested processes operating over many time scales and interacting across many levels of analysis (from genes, to parent interaction, to the structure of language, to social groups). The goal of this training program is to train scientists who can conduct programmatic and innovative research that integrates levels of analysis and that connects basic science to translational research. The training program seeks supports for five pre-doctoral and three postdoctoral trainees who will be drawn from fields in psychology, neuroscience, cognitive science, vision science, and speech and hearing sciences. Trainees will be supported for 2 years by the training grant. The training program is organized around collaborations that cut across levels of analyses and disciplines while focusing on a single problem. The training program is designed to build expertise in multiple methods - genetic analyses, behavioral studies, imaging, computational and statistical analyses - to the benefit of a deeper understanding of a target phenomenon and to provide training that fosters success, professionalism, and ethical conduct in both research and mentoring - including experiences in grant writing, article writing and reviewing, human subject safeguards, and evidence-based approaches to treatment and intervention.